Switch flake8 to github (gitlab was failing in CI)

.pre-commit-config.yaml

@@ -1,28 +1,34 @@
 repos:
--   repo: https://github.com/pre-commit/pre-commit-hooks
+  - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.0.1
     hooks:
-    -   id: check-case-conflict
-    -   id: check-executables-have-shebangs
-    -   id: check-merge-conflict
--   repo: git@github.com:elastic/apm-pipeline-library
+      - id: check-case-conflict
+      - id: check-executables-have-shebangs
+      - id: check-merge-conflict
+  - repo: git@github.com:elastic/apm-pipeline-library
     rev: current
     hooks:
-    -   id: check-bash-syntax
-    -   id: check-jenkins-pipelines
-    -   id: check-jjbb
--   repo: https://github.com/pre-commit/mirrors-mypy
+      - id: check-bash-syntax
+      - id: check-jenkins-pipelines
+      - id: check-jjbb
+  - repo: https://github.com/pre-commit/mirrors-mypy
     rev: v0.910
     hooks:
-    -   id: mypy
-        args: [--strict, --show-error-codes, --no-warn-unused-ignores, --implicit-reexport]
--   repo: https://github.com/ambv/black
+      - id: mypy
+        args:
+          [
+            --strict,
+            --show-error-codes,
+            --no-warn-unused-ignores,
+            --implicit-reexport,
+          ]
+  - repo: https://github.com/ambv/black
     rev: 21.6b0
     hooks:
-    -   id: black
+      - id: black
         language_version: python3
--   repo: https://gitlab.com/pycqa/flake8
+  - repo: https://github.com/pycqa/flake8
     rev: 3.9.2
     hooks:
-    -   id: flake8
-        exclude: tests|conftest.py|setup.py
+      - id: flake8
+        exclude: tests|conftest.py|setup.py